Development of 8-inch Key Processes for Insulated-Gate Bipolar Transistor

Based on the construction of the 8-inch fabricat ion line, advanced process technology of 8-inch wafer, as well as the fourth-generation high-voltage double-diffused metal-oxide semiconductor(DMOS+) insulated-gate bipolar transistor(IGBT) technology and the fifth-generation trench gate IGBT technology, have been developed, realizing a great-leap forward technological development for the manufacturing of high-voltage IGBT from 6-inch to 8-inch. The 1600 A/1.7 kV and 1500 A/3.3 kV IGBT modules have been successfully fabricated, qualified, and applied in rail transportation traction system.

A snapback suppressed reverse-conducting IGBT with uniform temperature distribution

A novel reverse-conducting insulated-gate bipolar transistor （RC-IGBT） featuring a floating P-plug is proposed. The P-plug is embedded in the n-buffer layer to obstruct the electron current from flowing directly to the n-collector, which achieves the hole emission from the p-collector at a small collector size and suppresses the snapback effectively. More- over, the current is uniformly distributed in the whole wafer at both IGBT mode and diode mode, which ensures the high temperature reliability of the RC-IGBT. Additionally, the P-plug acts as the base of the N-buffer/P-float/N-buffer transistor, which can be activated to extract the excessive carriers at the turn-off process. As the the simulation results show, for the proposed RC-IGBT, it achieves almost snapback-free output characteristics with a uniform current density and a uniform temperature distribution, which can greatly increase the reliability of the device.

A snapback-free TOL-RC-LIGBT with vertical P-collector and N-buffer design

A reverse-conducting lateral insulated-gate bipolar transistor （NI.2-LltJlS｜） with a trench oxide layer （IUL）, teaturlng a vertical N-buffer and P-collector is proposed. Firstly, the TOL enhances both of the surface and bulk electric fields of the N-drift region, thus the breakdown voltage （BV） is improved. Secondly, the vertical N-buffer layer increases the voltage drop VpN of the P-collector/N-buffer junction, thus the snapback is suppressed. Thirdly, the P-body and the vertical N-buffer act as the anode and the cathode, respectively, to conduct the reverse current, thus the inner diode is integrated. As shown by the simulation results, the proposed RC-LIGBT exhibits trapezoidal electric field distribution with BV of 342.4 V, which is increased by nearly 340% compared to the conventional RC-LIGBT with triangular electric fields of 100.2 V. Moreover, the snapback is eliminated by the vertical N-buffer layer design, thus the reliability of the device is improved.

A new short-anoded IGBT with high emission efficiency

A novel short-anoded insulated-gate bipolar transistor（SA-IGBT） with double emitters is proposed.At the on-state,the new structure shows extraordinarily high emission efficiency.Moreover,with a short-contacted anode,it further enhances the hole emission efficiency because of the crowding of the electrons.The forward voltage drop V_F of this structure is 1.74 V at a current density 100 of A/cm^2.Compared to the conventional NPT IGBT（1.94 V）,segment-anode IGBT（SA-NPN 2.1 V）,and conventional SA-IGBT（2.33 V）,V_F decreased by 10%,17%and 30%,respectively.Furthermore,no NDR has been detected comparing to the SA-IGBT.At the off-state, there is a channel for extracting excessive carriers in the drift region.The turn-off loss E_（off） of this proposed structure is 8.64 mJ/cm^2.Compared to the conventional NPT IGBT（15.3 mJ/cm^2）,SA-NPN IGBT（12.8 mJ/cm^2）, and SA-IGBT（12.1 mJ/cm^2）,E_（off） decreased by 43.7%,32%and 28%,respectively.

An improved trench gate super-junction IGBT with double emitter

An improved trench gate super-junction insulated-gate bipolar transistor is presented. The improved structure contains two emitter regions. The first emitter region of the device works as the conventional structure,which can absorb both the electron current and hole current. The second emitter on the top of the p-pillar acts as the hole current diverter, leading to an improved latch-up capability without sacrificing the off-state breakdown voltage（BV） and turn-off loss. The simulation shows that the latch-up limit of the SJ-IGBT increases from 15000 to 28300 A/cm^2 at VGE D10 V, the BV is 810 V, and the turn off loss is 6.5 m J/cm^2 at Von D1.2 V.